I'd like to use STI shifters on a 1979 road bike I got. However, I wonder if those integrated shifters could work properly when mated to the original center pull brakes, since current brake calipers can't fit properly.

Modern levers don't pull as much cable as their predecessors. On the plus side, that means more leverage, on the down side it calls for the brakes to be adjusted much more closely, which means that your wheel alignment is more critical.

I'd mount a single lever, wire it up and see how it plays out.

If these calipers don't work out, there are still long reach calipers that will fit and work.

Long- and extra-long-reach Tektro dual-pivot brake calipers are available from various suppliers.

You might have more of a problem with fitting the STI levers on the handlebars, which appear to be steel and thus incompatible with the clamping bands of the STI levers, which are designed for the larger diameter of standard aluminum handlebars.

I realize your location may limit the availability of more suitable bikes but that bike is going to cost way more to modernize than you think and the brakes are the least of it.

You will need:

STI shifters
Compatible rear derailleur
Compatible front derailleur
Compatible freewheel
Possibly a new rear wheel with a freehub and cassette
New matching chain
Probably a compatible handlebar and stem.

Consider all of this before proceeding. A newer, more modern bike may indeed be a better starting point.

There's a lot to be said for friction shifters on an old bike. They can be modernized but as others have pointed out, there can be problems with that. If you don't like downtube shifters, you could run friction bar end shifters.

In addition to the parts and complications already mentioned, the frame may also need to be spread to accommodate a new index-compatible freewheel or cassette. It's probably spaced at 120 or 126 mm. It'll need to be 126 mm minimum for 7 speeds; 130 mm for 7 or more.

And does the bike have a derailleur hanger? I'm not sure I would trust a claw-mounted derailleur to be precise enough for indexed shifting, more so as the number of speeds increases.

You'd also need downtube cable stops for brifters. If the bike has downtube shifter bosses, you can mount stops on those with built-in cable adjusters to fine-tune your derailleurs' indexing. If not, you'll have to use clamp-on cable stops and inline adjusters.

If the bike was made in the late '70s, I'd think the bars are going to be 23.8 mm regardless of whether they're steel or aluminum. The two bikes from that era with steel bars I've had in my garage -- an '81 Fuji and a '72-73 Peugeot -- both had 23.8 mm bars. Of course, it wouldn't hurt to measure to be on the safe side.

the Brakelevers shown fall in between , not as much pull as V brake type, but more than modern road brfters .

You could get better cable out the top brake levers, from premier brands... eBay, used C&V.. Modolo, Campagnolo, Shimano, early 70's... Minus the extension lever.

bars .. 23.8mm is like 1 /16th" bigger than 7/8" the 22. 2 that is the other typical tube size.

i would not put much money into this bike , the parts, retail, to do all you wish, is going to add up to be close to a new bike,

even starter road bikes, in bike shops..




...

Wow... I didn't knew all the expense needed for that project.

The rear axle is 126mm and it has a 5-speed freewhel, 14-28t. The 7 speed ones I can get here are also 14-28, so there's no gearing improvement beyond the index shifting.

I'd like to change the brake levers since they are busted. Now that STI brifters are not an option, What do you think about these other ones? And How can I know if they could work with the old center-pull brakes? Thanks.

You own them? Give it a try..

If the Lever pulls little cable , set the brake Pads Close to the Rim, so little cable pull is spent moving thru the gap to the rim..

with the pad to rim gap small, the wheel truing needs to be kept up.

A longer cable pull , the gap can be larger, and the rim can be out of true and still not hit the pads.



A fine tuning is getting the best Grip in your hand, where you have pad rim contact..

so you have best control , modulation .. and so forth..




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They will work better. You will have to run the cables under the bar tape since they're aero levers. Your current cables are misrouted in front of the bars anyway.

Since they're aero levers, you can add interrupter levers if you like.